A 'sand battery' stores clean heat to decarbonize industry

Much of industry's energy goes not into electricity but into heat, for drying, cooking, brewing and countless processes, and most of that heat still comes from burning fossil fuels. Storing renewable energy as heat is one of the simplest ways to clean it up. On January 30, 2026, Energy Storage reported that Finnish cleantech startup TheStorage had commissioned its first industrial-scale sand-based thermal energy storage system, installed at a brewery.

The concept, often called a sand battery, is elegantly low-tech. The system uses two insulated silos and an electric heater: cool sand flows from a cold silo through the heater, which is powered by renewable electricity, and the now-hot sand is stored in a second silo, holding heat at temperatures up to 800 degrees Celsius. When the factory needs heat, it is released on demand through a heat exchanger as steam or thermal oil, independent of whether the sun is shining or the wind is blowing at that moment. The design is scalable from 20 to 500 megawatt-hours, with charging power of 1 to 20 megawatts, and the company says its sand-in-motion approach transfers heat about ten times more efficiently than static storage.

“Storing renewable energy as heat is one of the simplest ways to clean it up.”

The promise is cheaper, cleaner industrial heat. TheStorage projects that the technology could cut industrial energy costs by up to 70% and emissions by as much as 90%, by letting factories soak up cheap renewable power when it is abundant and use the stored heat later. "Companies have wanted to decarbonize for years, but viable solutions simply weren't available," said CEO Timo Siukkola, framing the system as a long-missing piece for industries that run on heat.

The honest caveats are worth noting. These are the company's own projections, and a first commercial installation must prove its economics and reliability across years of real operation and across many industries with different heat needs. Sand-based storage also follows pioneers like Polar Night Energy, whose larger systems are still scaling. Even so, using something as ordinary as heated sand to store clean energy and decarbonize the hard-to-electrify world of industrial heat is exactly the kind of pragmatic innovation the energy transition needs. If it scales, the humble sand battery could help quietly clean up a huge slice of global emissions.